Move viewed file tooltip to the left; only show on hover

What does this MR do and why?

• Moves Viewed file tooltip to left so it's not covering up any buttons
• Moves focus from tooltip

Screenshots or screen recordings

Before	After

How to set up and validate locally

• Go to MR > changes
• Click viewed checkbox

Links

• ✂️ UX Paper Cuts 16.11 → Snippets & Paper Cuts ... (#425467 - closed)
• Viewed file tooltip covers up buttons on other ... (#454270 - closed)